This application claims priority from German Application No. 199 49 703.6, filed on Oct. 15, 1999, and German Application No. 100 10 601.3, filed on Mar. 3, 2000.
The invention relates first of all to a pressing tool with pressing levers which are connected to one another by a connecting link plate such that they can be rotated in a tong-like manner and each of which provides an upper free mouth end, there being provided a monitoring device which only allows an open position of the pressing levers which is suitable for the release of a blank to be achieved if a full pressing action, with a minimum closing position of the pressing levers being achieved in the process, has been carried out beforehand, a mechanical, electronic or electrical sensor being disposed on one of the pressing levers for the purpose of checking the relative positioning of the pressing levers in relation to one another.
Pressing tools of this type are known, radial pressing of blanks, for example sanitary fittings, that is to say the reduction in the tube or sleeve diameter, usually taking place by means of pressing tools with pressing levers and/or pressing jaws which are moved towards one another via cam tracks, located at the end located opposite a pressing jaws, and associated rollers of a conventional pressing machine. The operation of monitoring whether pressing has taken place in full proves problematic in the case of the radial pressing. In order to achieve the desired profile depth, full closure of the pressing jaws is necessary. An incomplete pressing action may have its basis, for example, in the power of the drive being too low. Furthermore, deformations or rupturing of the pressing jaws and/or pressing levers or damage to the pressing tool may result in incomplete closure of the pressing jaws. In this respect, different solutions for monitoring the pressing action which aim for interaction between drive machine and pressing jaws are known. It is thus known, for example, to provide a pressing jaw with a gap sensor which senses the closing position of the pressing jaw on the inner side remote from the mouth end and transmits a corresponding signal to the machine, which reacts suitably. Further solutions operate with a coding of the pressing jaws for example by magnets. In this case, monitoring of the position of the pressing jaw and of the associated end positions of the machine rollers is carried out by the machine, for which purpose it is necessary to have a displacement-measuring mechanism and evaluating logic system in the machine.
In relation to the prior art described above, a technical problem of the invention is seen as the provision of a pressing tool with pressing levers of the type in question which is improved as far as monitoring a full pressing action is concerned.
This problem is solved at least and in essence in the case of the subject matter of claim 1, this being based on the fact that the sensor is disposed in the upper free mouth end of the one pressing lever. As a result of this configuration, the closing position of the pressing lever and/or jaws in the region of the upper, free mouth ends, which are to be moved towards one another, is monitored. The pressing jaws are thus reliably monitored to the effect that they are fully closed towards the end of a pressing action. The sensor provided monitors here the spacing between the two mouth ends and only when a preferably fully closed position of the pressing jaws is achieved, that is to say when the mutually facing surfaces of the upper, free mouth ends, which are substantially the furthest away from the centre of rotation, butt against one another, does it allow an open position of the pressing jaws which is suitable for the release of a blank.
Since the sensor, for sensing the pressing-jaw position, is disposed in the region of the upper, free mouth end of a pressing lever, it is ensured, in contrast to the known solutions, that any rupturing of the pressing levers or pressing jaws in the front region is sensed since, in this case, there is no contact between the front ends, that is to say the upper, free mouth ends. It is preferred that, during a pressing operation, once a predetermined closing angle of the pressing levers in relation to one another has been achieved, opening of said levers for the release of the blank can only take place following full pressing action, that is to say following full closure of the pressing jaws. Accordingly, as from the predetermined closing-angle position, a full pressing action of the blank is absolutely necessary in order for the pressing tool to be removed thereafter. Such a principle is known in manual pressing tools, for example crimping tongs. These can only be opened again once the closed position has been achieved. The blocking mechanism used in these tongs preferably reacts to the angle position of the tool/tong handles. Since use is mostly made of a toggle-lever mechanism, a relatively precise check of the closed tongs is achieved, in this construction, even in the case of a relatively imprecise blocking catch. Since, in the case of the pressing levers which form the basis here, there is no such force enhancement, that is to say a lever advantage by virtue of toggle levers, the blocking mechanism has to be designed very precisely. This is achieved according to the invention by a division of the latching and blocking functions.
The invention also relates to a pressing tool with pressing levers which are connected to one another by a connecting link plate such that they can be rotated in a tong-like manner, with the interposition of a rolling body, and which define a mouth end, there being provided a monitoring device which only allows an open position of the pressing levers which is suitable for the release of a blank to be achieved if a full pressing action, with a minimum closing position of the pressing levers being achieved in the process, has been carried out beforehand, a mechanical release pin being disposed in one of the pressing levers for the purpose of checking the relative positioning of the pressing levers in relation to one another. In order to specify here a pressing tool with pressing levers of the type in question which is formed in improved manner as far as the monitoring of a full pressing action is concerned, it is proposed that the release pin interacts with a blocking slide which has a blocking pin, which blocking pin, if the pressing action is incomplete, prevents an opening movement of the pressing levers about the rolling body. As a result of this configuration, there is a mechanical locking if the minimum closing position of the pressing levers is not achieved. The sensor, which is disposed in the upper, free mouth of the one pressing lever, causes displacement of the blocking pin into the blocking position and securing of the blocking pin in this blocking position. The latter can be achieved, for example, in that the blocking pin engages in a recess of a tool which is secured in relation to the pressing lever or moves against the rolling body in the course of an attempted opening pivoting movement of the pressing lever.
The invention also relates to a pressing tool with pressing levers which are connected to one another by a connecting link plate such that they can be rotated in a tong-like manner and which define a -mouth end, there being provided a monitoring device which only allows an open position of the pressing levers which is suitable for the release of a blank to be achieved if a full pressing action, with a minimum closing position of the pressing levers being achieved in the process, has been carried out beforehand, a mechanical sensor being disposed in one of the pressing levers for the purpose of checking the relative position of the pressing levers in relation to one another, the mechanical sensor, in the case of incorrect closure of the pressing levers, triggering a mechanical locking mechanism in the region of the connecting link plate. In order to provide here a pressing tool with pressing levers of the type in question which is improved as far as the monitoring of a full pressing action is concerned, it is proposed that the locking mechanism be covered towards the outside by the connecting link plate. As a result of this, the locking mechanism, i.e. the means for blocking movement of the pressing levers into the open position, is positioned in a concealed location beneath the connecting link plate and, accordingly, protected against contamination and unauthorized manipulation. Furthermore, by virtue of this arrangement of the locking mechanism in the vicinity of the point of rotation, the lever forces acting on the components, in particular blocking pin, which bring about the locking action are kept low, this counteracting overloading of the blocking element or fatigue of the material of the same.
The invention additionally relates to a pressing tool with pressing levers which are connected to one another by a connecting link plate such that they can be rotated in a tong-like manner and each of which provides an upper, free mouth end, there being provided a monitoring device which only allows an open position of the pressing levers which is suitable for the release of a blank to be achieved if a full pressing action, with a minimum closing position of the pressing levers being achieved in the process, has been carried out beforehand, a mechanical, electronic or electrical sensor being disposed on one of the pressing levers for the purpose of checking the relative positioning of the pressing levers in relation to one another. According to the invention, a pressing tool with pressing levers of the type in question is advantageously developed to the effect that the monitoring device is disposed in its entirety in the interior of a pressing lever. As a result of this configuration, the monitoring device is advantageously protected against contamination and damage from the outside.
The invention also relates to a pressing tool with pressing levers according to the preamble of claim 1 in which in this case, for the advantageous development of a pressing tool of the type in question, it is proposed that the monitoring device be disposed in a sunken or planar manner in relation to the outer surface of the pressing lever, as a result of which the monitoring device does not adversely affect the thickness of the pressing-jaw.
The invention additionally relates to a pressing tool with pressing levers according to the preamble of claim 1. In order advantageously to develop a pressing tool of the type in question, it is proposed that the sensor, with the possible exception of a sensor tip, be disposed in the interior of a pressing lever. As a result of this configuration, the sensor is kept in a concealed position and is protected against damage and contamination. If appropriate, merely a sensor tip projects beyond the outer surface of the pressing lever.
The invention also relates to a pressing tool with pressing levers according to the preamble of claim 1 in which, for the advantageous development of the same, it is proposed that the sensor be disposed in a sunken or planar manner in relation to the outer surface of the pressing lever.
Irrespective of the configuration of the pressing tool according to the invention, it is also proposed that the sensor or the release pin be disposed in the upper, free mouth end of the one pressing lever. In the case of a pressing tool according to the invention in which the pressing levers are connected to one another such that they can be rotated in a tong-like manner, with the interposition of a rolling body, it is advantageously provided that the sensor or the release mechanism interacts with a blocking slide which has a blocking pin, which blocking pin, if the pressing action is incomplete, prevents an opening movement of the pressing levers about the rolling body. It is also advantageous, in the case of pressing tools of the type in question in which the sensor or the release mechanism, in the case of incorrect closure of the pressing levers, triggers a locking mechanism in the region of the connecting link plate, for the locking mechanism to be covered towards the outside by the connecting link plate. It is also advantageous for the monitoring device to be disposed in its entirety in the interior of a pressing lever. In addition, provision may also be made for the monitoring device to be disposed in a sunken or planar manner in relation to the outer surface of the pressing lever. In an advantageous development, provision is made for the sensor, with the possible exception of a sensor tip, to be disposed in the interior of a pressing lever. It is also proposed that the sensor be disposed in a sunken or planar manner in relation to the outer surface of the pressing lever. It proves advantageous for the sensor, if the pressing action is incomplete, to trigger mechanical blocking between the connecting link plate and the one pressing lever. As a result of this, the pressing lever which can be pivoted about a pin secured in the connecting link plate is blocked mechanically against the connecting link plate, which is stationary in relation to said pressing lever, said blocking action being brought about, for example, by means of a blocking element which is disposed in the preferably sensor-accommodating pressing lever and interacts with the connecting link plate for blocking purposes. In a preferred configuration, provision is made in this respect for a blocking slide to be disposed in the one pressing lever, with a blocking pin projecting in a recess of the connecting link plate, and for the blocking pin, if the pressing action is incomplete, to run against a blocking projecting portion in the recess of the connecting link plate. It is preferable here for the blocking slide, with the blocking pin, to be disposed in a concealed position of the pressing lever, with the blocking pin, in an overlap region of pressing lever and connecting link plate, projecting out of the pressing lever into the recess which is formed in this overlap region on that side of the connecting link plate which is directed towards the pressing lever. Said recess is preferably formed in a link-like manner, with a blocking projecting portion which can also preferably be overrun by the blocking pin during the pivoting movement of the pressing levers. If the pressing action is incomplete and an attempt is then made to open the pressing levers, said blocking projecting portion stands in the way of the pivoting path of the blocking pin, which is coupled to the pressing lever, with the result that an opening pivoting movement of the pressing levers can be effected at least only over a relatively small angle range, said angle range not however allowing the release of the blank. Provision is also made for the blocking slide to project under biassing action into the blocking position of the blocking pin, and said biassing can only be released in the case of a full pressing action. For this purpose, the blocking slide is preferably subjected to the action of a spring which spring, at the same time, makes it possible for the blocking pin, in the course of a pivoting closing movement of the pressing levers, to overrun the blocking projecting portion within the recess of the connecting link plate. A tension spring is further provided in this respect. In the case of full, correct pressing action, the biassing of the blocking slide into the blocking position of the blocking pin can be released by the sensor, which is disposed in the upper, free mouth end of the one pressing lever, for the purpose of overrunning the blocking projecting portion of the recess during the opening pivoting movement of the pressing levers. It proves advantageous in this respect for the blocking slide to be subjected to the action of a latching pin which, in the case of full pressing action, displaces the blocking slide into the release position. In this way, the division according to the invention of the latching and blocking functions is achieved, provision also preferably being made for the latching pin to be biassed into the release position of the blocking slide, and, in the case of full pressing action, for the biassing to be relieved. It is preferably the case here that the latching pin is subjected to the action of a compression spring which is loaded in the course of an opening pivoting movement of the pressing levers, following a full pressing action. The force of the spring which acts on the latching pin is here selected to be greater than that of the spring, in particular tension spring, which biasses the blocking slide, with the result that the latching pin, biassed in this way, in the case of a full pressing action and the associated release of the same, displaces the blocking slide and its blocking pin into the release position counter to the blocking-slide biassing. As has already been mentioned, build-up of the biassing of the latching pin is effected preferably in the course of an opening pivoting movement of the pressing jaw, following a full pressing action, in the manner of an energy store. It is preferred here, during this opening pivoting movement of the pressing levers, for the blocking slide and its blocking pin to be supported on a flank of the connecting-link-plate recess and, via the blocking slide, for the latching pin to be displaced, in its bearing bore or the like, into a latching position counter to the force of the compression spring which acts on said latching pin. It is also preferred for the sensor, in the upper, free mouth end of the one pressing lever, to be formed by a section of an end release pin which is disposed in the region of the end surface directed towards the other pressing lever, and it is also proposed in this respect that the latching pin be urged, by the release pin, into a blocking position, in which the biassing is inhibited, and, when the release pin is subjected to the action of the other pressing jaw, that the biassing be relieved for the purpose of displacing the blocking slide into the release position. It proves particularly advantageous here for the release pin itself to be subjected to biassing which urges the latching pin into the latching position and can be applied, for example, by means of a compression spring. In the case of full closure of the pressing levers, in which the mutually facing end surfaces of the pressing levers come into abutment, the release pin is subjected to the action of the other pressing lever, preferably by means of the end surface thereof which is directed towards the one pressing lever, such that the release pin is moved counter to its biassing, with the result that the latching pin is displaced into the release position, for the purposes of forcing the blocking slide into a position in which the blocking between blocking pin and blocking projecting portion is released. It proves particularly advantageous for the free end surface of the release pin which is to be acted on to be set back from that end surface of the pressing lever which is directed towards the other pressing lever, and for the opposite end surface of the other pressing lever, which brings about the release, to have a corresponding elevation. This avoids the situation where the latching pin passes into the release position by way of accidental contact with the release pin. In addition, in a further configuration of the subject matter of the invention, provision is made for an adjustable stop for the release pin to be disposed in the other pressing lever, this enabling precision adjustment of the unblocked position. Provision may also be made for the latching pin to be formed in one piece with the blocking slide. Furthermore, in an alternative configuration of the subject matter of the invention, it is proposed that the release pin has a run-on slope associated with the latching pin for the purpose of displacing the latching pin and/or the blocking slide into the release position during a pressing action. Alternatively, the configuration may also be selected such that the latching pin, which acts on the blocking slide or is formed in one piece therewith, has a run-on slope which interacts with the release pin for the purpose of displacing the latching pin. In order to keep the latching pin and/or the blocking slide with the blocking pin in the release position following a full pressing action over the entire opening pivoting path of the pressing levers, latching of the latching pin and/or of the blocking slide is advantageously provided, it being possible, in an exemplary configuration, for this to be achieved such that the latching pin engages in a latching recess of the release pin following displacement into the release position, it being possible for said latching recess of the release pin to be, for example, in the form of an annular groove into which a tip of the latching pin and/or of the blocking slide penetrates. In this latching position, the release pin, which forms a mechanical sensor, has been moved away from the sensor position, i.e. it cannot be subjected to the action of the stop, which is disposed in the other pressing lever. This latching position of the release pin is only achieved again in the course of further opening pivoting movement of the pressing levers, for which purpose provision is advantageously made for the release pin to be biassed into a sensor position, i.e. into a position which is subjected to the action of the stop of the other pressing lever. As an alternative to the abovementioned configuration where the release pin is set back in relation to the free end surface of the pressing lever associated with the release pin and the opposite stop, which brings about the release, projects beyond the associated end surface of the pressing lever, it is proposed that, when the pressing levers are moved together, both the release pin and the stop project beyond the associated end surface. It is also proposed that the blocking pin be spring-biassed into the blocking position. It proves particularly advantageous for the release pin, which can be released at an angle to the blocking pin, to have a run-on slope which, in the case of full pressing action, moves the blocking pin into the release position, preferably counter to the abovementioned spring-biassing. The blocking pin or the blocking slide is preferably disposed here at an obtuse angle to the release pin, within a common plane. An obtuse angle of from 80xc2x0 to 160xc2x0 is preferred. It also proves advantageous for the blocking pin, in the release position, to be secured by latching, the latching of the blocking pin also being released during the opening movement for the purpose of reactivating the monitoring device. The mechanical locking of the pressing levers, if the pressing action is incomplete, is achieved in a configuration according to the invention in that said mechanical locking is achieved by a blocking pin which is guided in the pressing jaw and projects into a recess provided in that side of the connecting link plate which is directed towards the pressing jaw. Accordingly, the blocking pin interacts with a component of the pressing tool which is rotationally fixed in relation to the pressing leversxe2x80x94the connecting link platexe2x80x94this configuration additionally providing for the locking mechanism to be covered towards the outside by the connecting link plate. If the pressing levers are connected to one another such that they can be rotated in a tong-like manner, with the interposition of a rolling body, then said rolling bodies are also overlapped by the connecting link plate. A further alternative locking method presents itself here, for which purpose it is proposed that associated recesses for the rolling body be formed in the pressing jaws, these leaving a free space between a recess and the rolling body during the closure of the pressing jaws, and that the blocking pin, which has moved into said free space, can only be moved into the release position by movement of the release pin which takes place during a full pressing action. Accordingly, following an incomplete pressing action, the blocking pin passes with blocking action into the free space between recess and rolling body, with the result that rotation of the pressing levers in the opening direction is prevented. In addition, it proves advantageous in this respect for two rolling bodies with associated recesses to be disposed one beside the other in the pressing jaws at different distances from the mouth. It is also proposed in this respect that the blocking pin interacts with the rolling body which is further away from the mouth. In order, following an incomplete pressing action and associated locking of the pressing levers, to enable removal of the pressing tool, for example in the case of damage to the blank or provision of an incorrect blank, in a further development of the subject matter according to the invention provision is made, following an incomplete pressing action, for it to be possible to achieve the release position of the blocking pin by an emergency unlocking action. This emergency unlocking action can preferably be carried out manually by the user. Provision is thus made for the emergency unlocking action to act on the release pin, which can displace the blocking pin into the release position. It is possible, for example, for an exposed handle connected to the release pin to be provided here. Alternatively, it is also possible for an emergency unlocking action to take place by displacement of the adjustable stop, which acts on the release pin. It is thus possible for an accompanying emergency unlocking handle to be fitted such that it acts rearwardly against the adjustable stop for the purpose of displacing the same in the direction of the release pin, as a result of which the latter is moved into the position in which the blocking pin is released. If the adjustable stop is in the form of an adjusting screw, said displacement for emergency unlocking purposes can be carried out by means of a rearwardly fitted screwing tool. It is also alternatively proposed for the emergency unlocking action to act directly on the blocking pin. It is thus possible, for example, for a handle, for emergency unlocking, to be associated with the release pin and/or the stop or the blocking pin, said handle accompanying the pressing tool as a loose part. Provision may also be made for the handle to be formed as an extension of the blocking pin and, for the pulling or pushing actuation of the blocking pin into the release position, to project laterally beyond the pressing lever. As a result of this configuration, the handle serving for emergency unlocking purposes is secured in captive fashion on the pressing tool, and, by virtue of the connection of the handle to the blocking pin, this, at the same time, provides a visual signal for registering the current position of the monitoring device. The pressing tool according to the invention formed in the manner described may, on account of the sensors and/or locking elements being disposed solely within it, be associated with a conventional, preferably electrically driven pressing machine. Alternatively, or even in combination therewith, provision may also be made for the sensor, which is disposed in the upper, free mouth end of the one pressing lever, to operate electrically or electronically. Until the full pressing action, i.e. until full closure of the mouth, takes place, an electric or electronic signal is supplied to the pressing machine acting on the pressing levers, or to the drive thereof, with the result that it is only following a full pressing action of a fitting or the like that said pressing machine switches off and moves back for the release of the pressing levers. This electronic control of the pressing machine via the electronic or electrical sensor disposed at the upper, free mouth end preferably operates in addition to the mechanical locking of the pressing levers. As a further configuration, a visual signal may be provided in the pressing tool in addition to mechanical locking and/or electronic sensor control of the pressing machine. It is thus possible for a part which is to be displaced preferably mechanically, thus, for example in the case of mechanical locking of the pressing levers, the blocking pin, to be visible, for example, through a viewing window, an initially visible, for example red-coloured, region indicating that the pressing action is incomplete. If this pressing action, in contrast, has been carried out correctly, then this results, via the sensor disposed in the upper, free mouth end, in a displacement of the part which can be seen through the window, for example the blocking pin, whereupon another, for example green-coloured, region becomes visible for the purpose of indicating this full pressing action. The entire mechanism is integrated in a pressing lever and, as a result, is protected against contamination. Any openings which may be necessary for the fitting of the mechanism or for emergency unlocking purposes are preferably closed. Alternatively, it is also possible for the mechanism to be protected against the penetration of dirt by cylindrical guides with narrow gaps. The mechanical monitoring device according to the invention can be used not just in the case of straightforward pressing jaws with fixed geometry but also in the case of closing jaws for closing-chain pressing tools and pressing jaws for exchangeable inserts.